Beginning of this year a downloadable book is available at the website of Microsoft. As stated in their abstract:
"This guide provides prescriptive guidance that can help you and your team build custom enterprise sites by using Microsoft Office SharePoint Server 2007 — such as company-wide portal sites or Internet presence sites. Custom sites based on Office SharePoint Server 2007 combine coded elements, such as workflows, document converters, and Web Parts, along with content, such as master pages, layout pages, graphics files, and Web pages. Best practices for developing these sites include setting up multiple environments for developing, integrating, piloting, and deploying coded elements and content from one environment to another. Therefore, coordinating the development and deployment of an enterprise site based on Office SharePoint Server 2007 is a complex activity. This guide describes the ways you can set up the multiple environments used in the development process and the methods for deploying content and code from one environment to another."
It also contains examples of other vendors and parties and how they made their solution. Like the Contoso's team approach.
http://go.microsoft.com/fwlink/?LinkId=110087